<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>02_JS变量与常量</title>
</head>
<body>
<script>
    var a = 10;
    console.log(a);
    var b=3.14;
    console.log(b);
    var c = 'hello world';
    console.log(c);
    var d = true;
    console.log(d);

    a=5.5;
    console.log(a);
    var a = "我来了";
    console.log(a);

    let x = 1;
    console.log(x);
    x=5.5;
    console.log(x);
    x='hello world';
    console.log(x);
    //let 定义的变量不能重复定义

    //const 不允许修改
    const y = 10;
    console.log(y);
    /*y=5;
    console.log(y);*/


</script>
</body>
</html>